The present invention relates to a carrier matrix, particularly for a catalytic reactor for the exhaust emission control in internal-combustion engines, having at least one carrier strip that has undulations in its transverse direction and of which the carrier matrix is wound and is then covered by a sheath.
A carrier matrix of this type is shown in German Unexamined Published Application 2,302,746. There, smooth strips are rolled off two delivery spools, one of said strips being Profiled by an undulating machine. Subsequently, the undulated and the smooth strip, via deflection rollers, are fed to a winding machine that winds the two strips onto a winding core. This results in a carrier matrix in which the smooth and the undulated strip wind themselves spirally around the winding core.
It is also shown in German Unexamined Published Application 2,856,030 to provide as the winding core a circular or an oval cylinder that, after the winding process, is pulled out of a carrier matrix. The resulting hollow space, after the winding process, is closed by pressing, the cross-section of the winding body being changed in the process. These changing possibilities are limited to elliptic or flat-oval shapes because otherwise the carrier strip itself would be deformed and damaged.
The above-described carrier matrices therefore have the disadvantage that they can have only circular or oval cross-sections. It is therefore not possible to fit the above carrier matrices into a given space in a motor vehicle, for example, in a drive shaft tunnel of a motor vehicle.
It is an objective of the invention to provide a metallic carrier matrix as well as a process and a device for its manufacturing, the carrier matrix having an arbitrarily suppliable cross-section and thus being optimally adaptable to existing spaces of a motor vehicle.
This and other objectives are achieved by a carrier matrix wound with a plurality of deflections of the carrier strip that are substantially in at least one longitudinally extending plane.
In a preferred embodiment, the planes in which the deflections are located intersect. This has the result that the carrier matrix can have, for example, trapezoid or triangular cross-sections. It is especially advantageous for the carrier strip to extend in a straight line in front of and behind the deflections. This makes possible for a matrix having a triangular cross-section, for example, the precise maintaining of desired angles.
An advantageous development of certain preferred embodiments of the invention is that the carrier matrix comprises several wound carrier matrix parts. This makes it possible to provide a carrier matrix having a cross-section with concave arching.
In a process for the manufacturing of a carrier matrix according to the invention, deflection means are inserted during the winding process between the wound layers of the carrier strip for providing the deflections of the carrier strip. In a preferred embodiment of this process, the deflections means are each successively inserted in the outer winding layer. Thus, the carrier strip by means of the deflecting means is lifted off the winding layer located under it and the deflection is developed by the placing of the carrier strip around the deflection means.
After the winding process, in preferred embodiments, the deflection means are removed out of the carrier matrix and the carrier matrix, while deforming takes place, is inserted into the sheath that has the final shape of the carrier matrix. The carrier matrix in this contemplated process is shaped into the shape of the sheath either before or during the insertion into the sheath. By this measure, hindrance by the deflection means of the exhaust gases that flow during operation through the carrier matrix, is prevented and therefore, the operability of the carrier matrix is not limited. At the same time, the desired cross-section of the carrier matrix that is produced by the deflection means is maintained.
In an advantageous further development of certain preferred embodiments, the distance of the deflection means over which the carrier strip is wound successively during the continuous winding, corresponds to the length of the carrier strip between the deflections, after the carrier matrix, while deforming is taking place, is inserted into the sheath. Thus, the physical position of the deflection means is not dependent on the desired cross-section of the carrier matrix, so that the deflection means may be inserted solely as a function of their distance between the winding layers of the carrier strip. In this case, it is especially advantageous to arrange the deflection means on lines in a star-shaped arrangement. As a result, it is possible to wind the carrier matrix with a high and uniform winding speed, without having to provide complicated winding drives.
Another advantageous development comprises providing the carrier strip before it is wound with weak points that are assigned to the deflections. This measure has the effect that the deflection points by means of the bends or perforations existing in the carrier strip can be developed even better and more precisely.
A preferred embodiment of a device for making a carrier matrix according to the invention comprises two disks connected with one another in a torsionally fixed manner by a rotating shaft. The device has a rotary drive, with at least one of the disks, at a distance from the axis of rotation, being provided with receiving means for the deflection means. By this arrangement, it is possible to produce the deflections at the same time with the winding of the carrier strip by inserting the deflection means. An especially advantageous feature of certain preferred embodiments is that the deflecting means are pins that move out from at least one disk into the winding area. A pin drive may be provided for the pins that can be switched corresponding to the progressing winding. It is also contemplated to equip the rotary drive with only one disk onto which the carrier strip is wound and into which the deflecting means are inserted.
In a further embodiment of this device, two coaxial pins are provided that each extend in parallel to the shaft of the disks and are arranged in the disks opposite one another. By this measure, a further automation and acceleration of the winding process is possible. It is especially advantageous for the outer surfaces of the pins to form deflecting edges. This results in a more precise fixing of the deflection points during the winding of the carrier strip.
Lastly, it is contemplated to provide a device for the deforming of the carrier matrix and for adapting of its shape to the shape of the sheath. By means of this device, the carrier matrix, after the pins that serve as the deflection means are removed, is either first deformed and then inserted into the sheath, or during the insertion into the sheath is at the same time deformed into the final shape of the carrier matrix.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings which show, for purposes of illustration only, an embodiment in accordance with the present invention.